Heinrici type stirling

[Dean W]

Hi all;

Thought I would share some pics of my current build, still very much in progress.  Not a complete build log here.  Just some
shots of the various parts and a few setups. 

This is from prints by the late Jerry Howell.  His family continues to operate the business, and they say all his products
will be available just as they were before his passing.
It's called a Duplex Vacuum engine, and is a Heinrici type beta engine.  Not a vacuum engine at all, but named so because it
was made in late 19th through early 20th century by the Duplex Vacuum Cleaner Co.

All these parts are made from bar stock using the 618 Atlas and Taig manual milling machine.
It still has quite a way to go.




Displacer arm and a couple of the crank rods.





The hot cap of stainless steel.





Milling out the bearing supports on the R/T.





And after much work with a Nicholson, nearly done.






Boring the cylinder.





And about finished but for the liner.





Here's a mock up of the parts thus far.  I have a few more things made.  I'll put up pics of
some more bits in a few days.

Thank you for having a look!

Dean

[Stilldrillin]

Dean,

You`ve made some beautiful parts there! 

I love all types of hot air engines. Looking forward to watching further progress...... 

David D

[Bernd]

Nice looking parts Dean. 

Those bearing supports, super work. All manually made right? No CNC involved in those curves?

Bernd

[Dean W]

David and Bernd, thanks!

Bernd, all manual machines, yes.  I run a clean shop.  No drugs, no CNC.


Dean

[Bernd]

I should have known better since I've been through your web site with a fine tooth comb and I didn't see one CNC. I think perhaps I had one of those senior moments. 

Many interesting projects there and much to get the mind working on using some of that info on my bigger machines.

Bernd

[Rob.Wilson]

Hi Dean 

WOW ,,,,,,,,,,,,,,,, very clean ,crisp work  to a high standard      I hope we will be seeing more of this engine build 


Regards Rob

[Dean W]

Bernd, thanks for the comments on the web site. 

Rob, I appreciate your nice remarks!

Here are a few more shots:



Con-rod and crankshaft being assembled with high strength sleeve retainer. 





Some of the various pins and rods.  The smaller ones are 1/16" dia.  I made a collet closer for the Atlas
a while back, and it sure came in handy for doing those wee pins.





Ground up a .022" circlip groove cutter to cut a couple of the pins for clips. 





Drilling to start a bored hole for the displacer can.





The displacer can and it's cap.  The can has a wall of .012".





Here's the displacer can complete





The parts so far.
Thanks for checking it out.  Will have some more in a couple of days.

Dean

[shoey51]

  just came accros this one 

looking forward to further instalments

Graham

[madjackghengis]

Looks like you've got a good start on an engine, Dean, looking forward to seeing how it all goes together and works.  Those are some fine looking parts you've machined. mad jack

[chuck foster]

wow 
you are doing some very fine machining...........i am sure jerry would be very pleased. 

chuck 

[MikeA]

Hello Dean,

Just found this thread and am enjoying your very nice craftsmanship - amazing stuff. Went through your website and got a number of ideas - I have an Atlas 618 and now have a Maximat V10P but can't bring myself to give up the little 618 - have to find a place to set up more equipment!

Best,
Mike

[Brass_Machine]

Wow Dean those parts look great! 

Even your swarf is neat! I mean look at how clean that is!

Eric

[Rob.Wilson]

  yep my thoughts 

Wow Dean those parts look great! 

Even your swarf is neat! I mean look at how clean that is!

Eric


Cheers Rob

[Dean W]

That's a bit of swarf porn fellows.  Best I can manage, anyway.

Thanks again for such nice remarks!

Dean

[Dean W]

A few more shots today, good people.




Turning/boring the cylinder liner.  It's about two inches long, and I did the boring first, then went to work on the
OD.  I put a piece of very wet paper towel in the finished bore to stop it from singing.  That drives me crazy.





That's it, done.  I made it for a .0005" interference, put the liner in the freezer and the cylinder in the toaster oven
at 300° f for 10 minutes, then pushed them together.  About halfway into the cylinder the brass started warming
up fast, and I had to use a little arbor press for the last bit.  Wasn't sure I was going to get it in.





But I got it run home with a bit of grunt on the press handle.





The piston is made of graphite, and I didn't have a collet to fit, so made a quick split collet from aluminum.  The position
was marked in the chuck so I could get it back in the same place, then it was taken to the mill and slit.





Then I could hold the piece of graphite firmly without worrying about crushing it.  After it was bored
and turned to a snug fit in the liner, I finished it off with a piece of index card.
I kept the shop vac nozzle over the tool post while cutting this piece.  Helped quite a bit, but still
had a light coat of black dust  everywhere.





That'll be it for today.  Here's the cylinder with its liner, the piston, and the split collet used to hold it.

Thanks for checking in!

Dean

[Dean W]

Hi all;
A few more pics of this project, today.



Turning the displacer shaft sleeve.  Fits in one end of the piston.





And turning up the piston wrist.  Fits in the other end of the piston.





The wrist gets a bit of milling.





Then those two bits go together with the piston and are all screwed together to form kind of like a sandwich.
I know this piston looks rough as a cob, but it is really, really smoooth.  And slikery.





When it's all put together, goes like this.
The displacer rod runs up and down through the center of the power piston.




The assembly, so far.

Thank you for looking in.

Dean

[Stilldrillin]

That`s all looking fabulous Dean!   

I`ve often wondered, in passing, how the "tandem piston" arrangement works..... 

I`ve almost got the idea, now! 

David D

[Bernd]

Impressive Dean.

Interesting looking linkage there. Ought to look great when running.

Bernd

[Rob.Wilson]

Stunning Dean 

M&M's never make it into my shop 


Regards Rob

[Dean W]

Thanks for your comments, fellows!

I have a few more updates on this construction.  
I'm going to use castings from PM Research (a company in the States) for the inner part of the flywheels.  I need to
make a couple of outer rims of steel to shrink onto the OD of these.  Haven't got to that part yet.
I couldn't hardly resist using these castings.  A 3.5" flywheel for $6 ain't bad.



Setup for drilling and tapping for the set screws.  When I put set screws, (grub screws) against a crank shaft, as will
be done for these flywheels, I put a small lead shot in the threaded hole first.  Keeps the set screw from scarring the
shaft.





Next, some squaring and boring for the top of the firebox.  The engine assembly gets mounted to this piece via the
four holes in the corners.





The gaskets that go between the hot cap and the rest of the engine were cut from ceramic fiber sheet.
This stuff is available here as a substitute for asbestos.  I can post the U.S. suppliers' contact info if
anyone would like it.





Cutting out the sides of the firebox, I began with a hack saw.  That was taking way too long by the time
I had got one of the four needed cut out.





The remaining three were cut out on the mill.  A lot faster.
Too soon old, too late smart!  I eventually figure this stuff out..





After the four pieces are cut to shape, the corners are filed to a 45° bevel.  Again, I did the first
couple using only the file.  The rest were roughed off with the bench grinder, then cleaned up to
the proper angle with a file.  





After the pieces are all filed, the bevels make for a nice fit-up.  
Much to do on these yet before they can be soldered up.

That's it for now.
Thanks for looking in.

Dean

[madjackghengis]

Hi Dean, that is one of the most interesting arrangements for a Stirling engine I've seen, and you're doing a great job on it, nice detail work and nice finish to the machined parts.  Looking forward to seeing it together, first of all, and then the run video.  That tandem piston setup is almost like a "Ringbom" Stirling, it looks like, using the same cylinder for both displacer and power piston.  Great work mad jack

[Dean W]

Hi Jack, and thanks for the kind remarks! 
The setup is kind of like a Ringbom, I guess, except on this one, the con rods for the displacer can and the power piston run concentric in the bore, and they both have their own rod throws, one connected to the crank, and one to another crank that runs off of the linkage off one end of a flywheel.  They run out of phase so the piston and displacer don't meet in the middle, one going up, the other going down.
It's an interesting mess. ;)
Appreciate your comments!

Dean

[madjackghengis]

Hi Dean, I've been studying Stirlings for some years now, for modeling purposes as well as the possibility of building one of useful size and power, but this is the first time I've seen this particular arrangement of the linkage, and you're right, it only resembles a Ringbom, it is an entirely different beast, and I really look forward to seeing it spinning under its own power.  Bernd said the linkage ought to look very interesting while its running, and I would have to second that.  It is the most interesting arrangement I've seen recent enough to remember, and I may very well try to duplicate your work and build one on that design myself, when I get done with the radial, the steam engine I started a couple years ago and didn't finish, it's just a matter of figuring out where it fits in the list of "to be done" projects which grows at about the same rate as my stack of books to read.  I'm thinking you might try going into overtime so you can get this done twice as fast, and we can see it spinning twice as soon, you do some very nice work, and its a truly unique build, inspiring. mad jack

[Dean W]

Hello fellows;

A few more pics.  Making a bit of progress.



After I know the pieces all fit well, they get stacked on the mill table, and bored for the arc that will show
in the bottom of the firebox/base.





One of the pieces gets a slot milled so the burner can slid in.





I twisted some single strand tie wire into a tight two strand braid, and wired up the four sides.  The braided wire
will stay put much better than a single strand of regular tie wire.  Flux, and four little bits of 56% silver brazing
wire, and heat it!





The sides are 1/8" CRS, and it took a while to get it up to heat.  I used two Bernzomatic type plumbers torches.
They are just the regular kind that take 1lb disposable cylinders.  I put MAPP gas in one of them to get a little
extra heat.  Isn't that just like an ol' rod burner.. More rod!  More heat!   (More money!)  ; )





Then did the same for the bottom corners.  The sides between the top and bottom corners will just get filled with
regular 96/4 solder. 





Then onto the mill to take a skim off the top so the engine base piece will sit nice and flat.





I put on the top the same way, with hard silver wire.  After this was done, all the edges got the regular
solder, and everything was filed nice and flat.





The flywheels I got from PMR are nice, but not large nor heavy enough.  So, turned up a couple of steel
rims from a piece of DOM, then skimmed the flywheel centers to fit the rims.





Another assembly shot.  Still half a dozen pieces to make, but it's getting there!

Thanks for looking,

Dean

[sbwhart]

Great work I like how you fabricated the tower.

Stew